Web provisioning software has been developed to build Web sites for the Internet and intranets. Web provisioning generally includes selecting a site template that defines the structure and the content of a Web site. Based on the content of the site template, Web provisioning software populates the initial page, the directories, and the site structures of the Web site. Web provisioning software enables a user to create multiple Web sites from a single, predefined site template. As a result, predefined site templates enable a user to quickly create Web sites without spending a substantial amount of time deciding how the sites should look or function.
In some platforms suitable for Web provisioning, such as Microsoft Windows SharePoint Services®, a Web site can only use provisioning information from the site template that initially provisioned the Web site. While the site template serves as a foundation, the site template limits the functionalities that can be added to the provisioned Web site. The Web site is constrained to the set of functionalities included in the site template. The Web site cannot be modified to support functionalities different from the functionalities provided by the site template. Given that business requirements for a Web site may change from time to time, a Web site may be required to evolve during its lifetime. Part of the evolution may require that the Web site functionalities change. Many types of Web page functionalities are provided by control components (“controls”). Controls are active Web page components that respond to user input requesting the performance of specific tasks, such as the selection of an option, text entry, or search. Controls are modular in nature with well-defined interfaces and may be used in many different Web pages that require the same functionality. The behavior and appearance of Web page controls may be specified using properties. Setting the properties of a control to a predefined value causes the control to appear or behave in certain predefined manners. For example, a property of a control may specify the size of the control. Another property of the control may specify certain default behavior of the control, such as showing a default selection of an item in a list presented by the control to a user. Customizing a Web page to fit a particular need often requires using custom control components.
Web site provisioning software makes it easy to create new Web sites to match end-user needs. However, the large number of Web sites created using such software can create new manageability and extensibility problems. For example, third party Web applications may need to globally replace certain sections or components of a Web page with the third party's own custom section or component. For instance, a third party provider of a search application may want to replace a standard search application component with a more advanced search application component that features more capabilities and better user interface elements. Typically, replacing a standard search application requires that the advanced search application provider modify each instance of a page that contains the standard search application. Because of the large number of Web pages included in many Web sites, this process can be time-consuming and is often error-prone.